Compressor



E. EGLI COMPRES SOR Feb. 27, 1934.

Filed April 14, 1932 Patentecl Feb. 27, 1934 UNITED STATES PATENT OFFICE Application April 14, 1932, Serial No. 605,314 In Germany April 18, 1931 16 Claims.

Applcations have been filed in Germany, April 18, 1931; Austria, March 14, 1932; France, March 16, 1932; and Belgium, March 18, 1932.

The provsion of automatically acting no-load starting devices in compressors makes it possible to start up with a small torque and therefore to make the starting device of small dimensions.

Similar arrangements are already known, which however have the disadvantage that at the first starting up ci the compressor the starting valve does not yet become operative.

The present invention relates to an automatically acting no-load starting valve for compressors, which, when the engine is stationary, closes the suction branch owing to the pressure of a spring. After starting up the valve opens again under the influence of the vacuum on the suction side and is kept open while the plant is in operation through the pressure on the delivery side.

As compared with the known constructions the invention has the advantage that already at the first starting up of the engine the valve is closed, so that there is no danger of damage to the elec-. tric starter which is designed only for the starting current at no-load. Furthermore, should for any reason, for instance owing to the compressor or a pipe becoming leaky, the production of the vacuum in the suction branch or of the pressure in the delivery branch fail, the valve automatically separates the pressure side from the suction side.

In the drawing:-

Figure 1 illustrates a schematic view, partly in section, showing one form of the invention.

Figure 2 illustrates a similar view showing modfications of certain parts of the arrangement shown in Figure 1.

Figure 3 illustrates a schematic view, partly in section, showing a still further modified form 40 of the invention.

A typical rotary compressor 1 is shown in connecton with the controlling device properly forming this invention, this compressor having the usual suction and exhaust or outlet ppes.

The valve 2 is kept closed by the spring 3 when the engine is stationary and is controlled by the piston 4. The space 5 above this piston communicates through the pipe 6 with the part 1 of the suction branch. When starting up, a vacuum is produced in both spaces 7 and 5, which influences the piston 4 and opens the valve 2. The opening of the valve is only to take place when the engine has reached its full revolutions. A corresponding retardation may be produced in various ways. By connecting tor instance the space 5 through the pipe -8 with the atmosphere or the suction side 9 and causng atmospheric air.

to flow in, the time taken to evacuate the space 5 may be regulated at Will by means of the throttling cocks 10 and 11. The valve only moves after a definite degree of vacuum has been reached. The air which has been compressed in the compression space 12 flovvs during the no-load period of the compressor through the by-pass 13 and the overflow valve 14 back into the suction pipe 9. After the valve 2 has opened the vacuum in the suction branch drops and the valve would close again owng to the pressure of the spring. In order to prevent this, the space 15 below the piston 4 is connected by the pipe 16 with the com- 0 presson side of the compressor, so that the pressure keeps the valve open during the operative period. In many cases it is of advantage to withdraw the pressure at a suitable point 17 of the compression space, at which the desirecl amount of pressure is available.

In order to prevent the rapid opening and closing of the valve and the consequent loacling and unloading shocks, the valve may be operated by pressure oil, as is shown by way of example in 30 Fig. 2. For this purpose oil-filled intermediate vessels 18 and 19 are interposed in the compressed air pipe 16 and in the suction pipe 6. On starting up the compressor, the oil is, owing to the vacuum in the pipe 6, drawn by suction 35 from the space 5 into the vessel 18, so that the piston 4 rises and opens the valve 2. For keeping the valve open-in this case pressure oil from the vessel 19 is used, which is connected to the compressecl air pipe 16. The valve motion may be retarcled to any desired extent by throttling the fiow of oil by means of a cock 20 01 26.

The described starting device can be very simply combined with means for regulating the output, which are interposed in a known manner on the suction side of the compressor and which on a certain pressure being reached in the delivery pipe close the suction branch and cause the compressor to run idle. Fig. 3 shows by way of example an arrangement ci such a constructional form. The auxilary controlling means 21 connect the pipes 6, 8 and 22 with one another, so that the above-described starting condition is obtained. Should the pressure in the delivery branch 23 and in the pipe 24 increase too greatly during Operation, the auxiliary controlling means 21 which are loaded by a weight 25 are raised and the pipes 6 and 8 are closed, while at the same time the pipe 24 is connected to the pipe 22 and the space 5. The pressure in the space 23 acts on the upper side of the piston 4. Consequently the valve 2 closes and remains in the no-loacl position until the pressure in the branch 23 has sunk to such an extent that the weight 25 can cause the auxiliary controlling means to sink again. The valve thereupon opens again, as during the starting periodi.

What I claim is:

1. In apparatuS for starting c'ompressors uncler no-load conditions, the combination with a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening tovvards the compressor, spring means urging the valve to close, a cylinder alinecl with the valve on the side towarcls the compressor, a piston in said cylinder having a rod connected with said valve, and means to establish pistonoperative communication between a point on the suotion pipe located between the valve and compressor and a point on the cylinder at the side of the piston remote from the valve.

2. In apparatus for starting compressore under no-load conditions, the combination With a compres'sor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening to- Warols the compressor, spring means urging the valve to close, a cylinder alined. With the valve on the side t0warcls the compressor, a piston in said cylinder having a rocl connected with said valve, and a duct leading from a point in the suction pipe between the valve and compressor to a point in the cylinder on the side of the piston remote from the valve.

3. In apparatus for starting compressore under no'-load conditions, the combinat-ion With a compressor having an inlet pipe and an exhaust pipe; of a valve in" the suction pipe opening towards the compressor, spring means urging the valve to close, 3; cylinder alined With the valve on the side towards the compressor, a piston in said cylinder having a rod connected withsaid valve, a closed fluid containing reservoir communicating with the cylinder on the side of the pistonremote from the valve, and a duci; leading from a point on the suction pipe between the valve and the compressor to the reservoir above the fluid therein.

4. In apparatus for starting compressors under no-loacl conditions, the combination witha compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a cylinder alined With the valve on the side towards the compressor, a piston in saideylincler having a rod connected with said valve, a duci: leading from apoint in thesuction pipe between the valve and compressor to a point in the cylinder on the side of the piston remote from the valve, a valve insaid duct, and a pressure regulator czpntrolling the opening and olosing the last mentionedvalva 5. In apparatus fo-r starting compressore under no-load conditions, the combination with a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urg-ing the valve to close, a cylinder alinecl With the valve on the side tovvards the compressor, a piston in said cylinder having a rod connected "with said valve, means to establish pistonoperative communicati0n between apoint on the suction pipe located between the valve and compressor and a point on the cylof the compressor and the cylinder on the side of the piston adjacent said valve.

6. In apparatus for starbing compressore under no-loaol conditions, the combination with a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a cylinder alined With the valve on the side towards the compressor, a piston in said cylinder having a rod connected With said valve, a duci; leading from a point in the suction pipe between the valve and compressor to a point in the cylinder on the side of the piston remote from the valve, and.' a second duct leaoling from the compression side of the compressor to the cylinder on the side of the piston acljacent the valve.

7. In apparatus for starting compressore under no-load conditions, the combination With a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a,cylinder alined with the valve on the side towards the compressor, a piston in said cylinder having a rod conneoted vvith said valve, a closed fiuid. containing reservor communicating with the cylinder on the side of the piston remote from the valve, a duci: leading from a point on the suction pipe between the valve and the compressor tothe reservoir abovethe fiuid therein, a seconcl closed fluid containing reservoir communicating With the cylinder on the side of the piston ad jacent the valve, and a second duci; leading from the pressure side of the compressor to the second reservoir above the fluid. therein.

8. In apparatus for starting compressors under no-load conditions, the combination With a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a cylinder alined With the valve on the side towards the compressor, a piston in said cylinder having a rod. connected vvth said valve, a duci: leading from a 'point in the suction pipe between the valve and compressor to a point in the cylinder on the side of the piston remote from the valve, a second duct leading from the compression side of the compressor to the cylinder on the side of the piston adjacent the valve, a valve in said first duct, and a pressure regulator controlling the opening and closing of the last mentioned valve.

9. In apparatus for starting compressors under no-load. conditions, the combination with a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a cylinder alined with the valve on the side towards the compressor, a piston in said cylinder having a rod connected With said valve, means to establish piston operative communication between a point on the suction pipe located between the valve and compressor and a point on the cylinder at the side of the piston remote from the valve, a by-pass duci; leading from the exhaust pipe to a point on the suction pipe more remote from the compressor than the first valve, a by-pass valve controlling the by-pass duci), and means connecting the first valve and the by-pass valve and closing one valve as the other opens.

10. In apparatus for starting compressors under no-load conditions, the combination With a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a cylinder alinecl With the valve on the side towards the compressor, a piston in said cylinder having a rocl eonnected with said valve, a duci; leading from a point in the suction pipe between the valve ami compressor to a point in the cylinder on the side of the piston remote from the valve, a by-pass duci: leacling from the exhaust pipe te a point on the suction pipe more remote from the compressor than the first valve, a bypass valve controlling the by-pass duct, and means connecting the flrst valve and the by-pass valve ancl closing one valve as the other epens.

11. In apparatus for starting compressore under no-load conditions, the combination with a compressor having an inlet pipe and an exhaust pipe; o-f a valve in the sucton pipe opening towards the compressor, spring means urging the valve to close, a cylinder alined With the valve on the side towards the compressor, a piston in said cylinder having a rocl connected With saicl valve, a closed fiuicl containing reservoir communieating With the cylinder on the side of the piston remote irom the valve, a duci; leacling rom a point on the suction pipe betvveen the valve and the compressor to the reservoir above the fluid therein, a by-pass duci; leacling irom the exhaus; pipe 130 a point on the suetion pipe more remote from the compressor than the first valve, a by-pass valve controlling the by-pass duci, anol means connecting the first valve and the by-pass valve and closing one valve as the ether opens.

12. In apparatus fcr starting compressore under no-load conditions, the combination With a uompressor having an inlet pipe and an exhausi. pipe; of a valve in che suction pipe opening tovvards the compresser, spring means urging the valve to close, a cylinder alined Wth the valve on the side towarcls the compressor, a piston in saicl cylinder having a red conneeted With said valve, a duct leading from a point in the suction pipe between the valve and compressor te a point in the cylindei on the side ci the piston remote from the valve, a valve in said cluct, a pressure regulator centrolling the opening and closing the last mentioned. valve, a by-pass duct leading from the exhaust pipe to a point on the suction pipe more remote from the compressor than the first valve, a by-pass valve conirolling the by-pass duct, ancl means connecting the first valve and the by-pass valve and closing one valve as the other opens.

13. In apparatus for startng compressore under no-load c0nclitions, the combination Witli a compressor having an inlet pipe and an exhaust pipe; ci a valve in the suetion pipe opening towards the compreesor, spring means urging the valve to close, a cylinder alinecl With the valve 011 the side tovvarcls ine compressor, a piston in said cylincler having a iod connected With said. valve, means 130 establish pisbon operative communication between a point on the suction pipe located between the valve ami compressor and a point on the cylinder at the side ef the piston remote from the valve, C'-bel means to establish piston operating cemmunication betvveen the pressure side of the ccrnpressor and the cylinder on the side of the piston adjacent saicl valve, a by-pass duci; leacling from the exhaust pipe te a potei; on the sucton pipe more remote from the compressor than the firsi, valve, a by-pass valve controlling the loy-pass duci, ami means connecting the first valve and the by-pass valve and closing one valve as the other opens.

14. In apparatus for starting compressors under no-load conditions, the combinaton with a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening tovvards the compressor, spring means urging the valve to close, a cylinder alined. with the valve on the side towards the compressor, a piston in said cylinder having a rod. connected With said. valve, a duct leading from a point in the suction pipe between the valve and compressor to a point in the cylinder on the side of the piston remote from the valve, a second duci: leading from the compression side of the compressor to the cylinder on the side of the piston adjacent; che valve, a by-pass duet leading from the exhaust pipe to a point on the suetion pipe more remote from the compressor than the first valve, a bypass valve contrelling the loy-pass duct, and. means connecting the first valve and the by-pass valve ancl closing one valve as the other opens.

15. In apparatus for starting compressore under no-load conditions, the combination wth a compresscr having an inlet pipe and an exhaust pipe; of a valve in the suctien pipe opening tewards the cempressor, spring means urging the valve to close, a cylinder alinecl With the valve on the side towards the compressor, a piston in salti cylinder having a rodi connected Wth said valve, a closecl fluidi containing reservoir communicating With the cylinder on the side of the piston remote from the valve, a duci leading from a pcint on the suction pipe between the valve and the compressor to the reservoir above the fiuicl therein, a seconol closed fluicl containing reservoir communicating With the cylinder on the side ci che piston adjacent the valve, a second duct leading from the pressure side ci the compressor to the second reservoir above the fiuid therein, a by-pass duci leading from the exhaust pipe te a point on the suction pipe more remote from the compressor than the first valve, a by-pass valve eontrolling the by-pass duct, end. means connecting the first valve and the by-pass valve anol closing one valve as the other opens.

16.In apparatus for starting compressore under no-load conditions, the combination With a compressor having an inlet pipe and an exhaust pipe; of a valve in the suction pipe opening towards the compressor, spring means urging the valve to close, a eylinder alined wth the valve on the side towards the compressor, a pston in saicl cylinder having a rocl conneeted Wth saicl valve, a duct leading from a point in the suction pipe between the valve ancl compressor te a point in the cylincler on the side of the piston remote from the valve, a second duct leading from the compression side of the compressor to the cylinder on the side of the piston adjacent the valve, a valve in saicl first duct, a pressure regulator controlling the opening ancl closing of the last mentioned valve, a loy-pass duci: leading from the exhausi: pipe to a point on the sucton pipe more remote from the compressor than the first valve, a by-pass valve controlling the by-pass duct, and means connecting the first valve and the by-pass valve and closing one valve as the other opens.

EUG-EN EGLI. 

